Research

Both the external world and our internal world are full of changing activities , and the question of how these two dynamic systems are linked constitutes the most intriguing and fundamental question in neuroscience and cognitive science. This study specifically investigates the processing and representation of sound dynamic information in human auditory cortex using magnetoencephalography (MEG), a non-invasive brain imaging technique whose high temporal resolution (on the order of ~1ms) makes it an appropriate tool for studying the neural correlates of dynamic auditory information. The other goal of this study is to understand the essence of the macroscopic activities reflected in non-invasive brain imaging experiments, specifically focusing on MEG. Invasive single-cell recordings in animals have yielded a large amount of information about how the brain works at a microscopic level. However, there still exist large gaps in our understanding of the relationship between the activities recorded at the microscopic level in animals and at the macroscopic level in humans, which have yet to be reconciled in terms of their different spatial scales and activities format, making a unified knowledge framework still unsuccessful. In this study, natural speech sentences and sounds containing speech-like temporal dynamic features are employed to probe the human auditory system. The recorded MEG signal is found to be well correlated with the stimulus dynamics via amplitude modulation (AM) and/or phase modulation (PM) mechanisms. Specifically, oscillations at various frequency bands are found to be the main information-carrying elements of the MEG signal, and the two major parameters of these endogenous brain rhythms, amplitude and phase, are modulated by incoming sensory stimulus dynamics, corresponding to AM and PM mechanism, to track sound dynamics. Crucially, such modulation tracking is found to be correlated with human perception and behavior. This study suggests that these two dynamic and complex systems, the external and internal worlds, systematically communicate and are coupled via modulation mechanism, leading to a reverberating flow of information embedded in oscillating waves in human cortex. The results also have implications for brain imaging studies, suggesting that these recorded macroscopic activities reflect brain state, the more close neural correlate of high-level cognitive behavior.

This paper presents three experiments which examine the effect of lexical surface frequency on sentence processing and the interaction between surface frequency and syntactic prediction. The first two experiments make use of the self-paced reading paradigm to show that processing time differences due to surface frequency (e.g., the frequency of cats not including occurrences of cat), which have previously been demonstrated in isolated word tasks like lexical decision, also give rise to reaction time differences in sentence processing tasks, in this case for singular and plural English nouns. The second experiment investigates whether a prediction for the number morpheme triggered by the number-marked determiners this and these might counter the surface frequency effect; however, the small size of the surface frequency effect and baseline differences in reaction times to this and these made the results unclear. Results from a third experiment using lexical decision suggest that the difference in the size of the surface frequency effects between the lexical decision experiments and the self-paced-reading experiments are likely due to differences in task demands. Our results have methodological implications for psycholinguistic experiments that manipulate morphology as a means of examining other questions of interest.

The aim of this thesis is to contribute to the understanding of the nature of finiteness and A-movement by looking at control phenomena in Japanese, where verbal morphology sometimes does not help to identify finiteness of clauses. In so doing, the thesis addresses empirical and theoretical questions that arise from analyses of Japanese control and attempts to resolve them. The first part of the thesis, chapter 2, investigates obligatory control (OC) into tensed clauses, where embedded predicates are morphosyntactically marked for tense. Recent findings about the obligatory control/non-obligatory control dichotomy leads to the observation that tensed subordinate clauses that either cannot support past tense or present tense trigger OC and raising. It is proposed that this effect comes from the defective nature of T of such clauses and that this nonfinite T triggers OC and raising. It is shown then that the movement theory of control facilitates to instantiate this proposal and to give a principled account of a wide range of the data. Chapter 3 concerns issues of controller choice with special reference to embedded mood constructions, where mood markers are overtly realized. It is observed that controller choice is systematically correlated with the mood interpretation of complement clauses. While Japanese allows split control in the exhortative mood construction, the language lacks the mood maker that should exist if subject control over intervening objects were possible. The lack of the nonexistent mood marker is derived by the Principle of Minimal Distance. Also, a preliminary movement-based analysis is given to the actual distribution of split control. The final chapter aims to provide an empirical argument for selecting a movement theory of control over PRO-based theories by closely examining backward control and related constructions. While establishing that backward obligatory control exists in Japanese, the chapter shows that the data argue for a copy theory of movement, combined with a particular theory of chain linearization. The hypothesis that economy plays a crucial role in determining how to pronounce chains is shown to explain properties of the classic Harada/Kuroda style analysis of Counter Equi.

This thesis aims to reveal the mechanisms and constraints involving in long-distance dependency formation in the static knowledge of language and in real-time sentence processing. Special attention is paid to the grammar and processing of island constraints. Several experiments show that in a head-final language like Japanese global constraints like island constraints are applied long before decisive information such as verb heads and relative heads, are encountered. Based on this observation, the thesis argues that there is a powerful predictive mechanism at work behind real time sentence processing. A model of this predictive mechanism is proposed. This thesis examines the nature of several island constraints, specifically Complex NP Islands induced by relative clauses, and clausal adjunct islands. It is argued that in the majority of languages, both relative clauses and adjunct clauses are islands, but there is a small subset of languages (including Japanese, Korean and Malayalam) where extraction out of adjunct clauses seems to be allowed. Applying well-established syntactic tests to the necessary constructions in Japanese, it is established that dependencies crossing adjunct clauses are indeed created by movement operations, and still the extraction is allowed from adjuncts. Building on previous findings, the thesis turns to the investigation of the interaction between real time sentence processing and island constraints. Looking specifically at Japanese, a head-final language this thesis ask how the structure of sentences are built and what constraints are applied to the structure building process. A series of experiments shows that in Japanese, even before high-information bearing units such as verbs, relative heads or adjunct markers are encountered, the structural skeleton is built, and such pre-computed structures are highly articulated. It is shown that structural constraints on long-distance dependencies are imposed on the pre-built structure. It is further shown that this finding support the incrementality of sentence processing.

In parasitic-gap constructions an illicit gap inside a syntactic island becomes acceptable in combination with an additional licit gap, a result that has interesting implications for theories of grammar. Such constructions hold even greater interest for the question of the relation between grammatical knowledge and real-time language processing. This article presents results from two experiments on parasitic-gap constructions in English in which the parasitic gap appears inside a subject island, before the licensing gap. An offline study confirms that parasitic gaps are acceptable when they occur inside theinfinitival complement of a subject NP, but not when they occur inside a finite relative clause. An on-line self-paced reading study using a plausibility manipulation technique shows that incremental positing of gaps inside islands occurs in just those environments where parasitic gaps are acceptable. The fact that parasitic gaps are constructed incrementally in language processing presents a challenge for attempts to explain subject islands as epiphenomena of constraints on language processing and also helps to resolve apparent conflicts in previous studies of the role of island constraints in parsing.

This dissertation is a case study of the syntax of the left periphery, using exclamatives in English and Japanese. In the first part, I discuss exclamatives in Japanese in detail by focusing on the properties of the exclamative wh-phrases and particles that function as licensors for wh-phrases in exclamatives. We argue that licensing exclamatives involves at least three functional heads: Finite, Focus, and Mood. Especially, the necessity of the Mood head differentiates exclamatives from interrogatives. On the other hand, we claim that having these three functional projections does not type the clause as exclamative, and show that the presence of a wh-phrase of a distinct form is in fact a crucial part of the clause-typing for exclamation. This conclusion supports the claim that clause type should not be directly encoded into syntax as an independent functional category. The second part of dissertation deals with English exclamatives. We show that sluicing is available in English exclamatives, suggesting that focus is playing a role for the availability of sluicing, assuming that both interrogatives and exclamatives involve focus. Another conclusion about English exclamatives is that exclamative wh-clauses are licensed, not by selection, but by being c-commanded by a factive operator or a factive predicate. This goes against the traditional observation; our conclusion is empirically justified based on the observation that it is possible to license exclamative wh-clauses by a non-local licensor. We argue that this property is similar to what has been observed for the aggressively non-D-linked wh-phrases, accounting for the distribution and behavior of those non-standard wh-phrases. Finally, we investigate how Japanese exclamatives are processed by native speakers of Japanese with an on-line self-paced reading study and two off-line sentence fragment completion studies on the processing of wh-exclamative sentences in Japanese. These studies investigate the real-time formation of sentential structures with higher functional categories, and show that the parser immediately engages to build syntactic structures with discourse-oriented higher functional projections before coming across the head, favoring the incremental processing model.

This dissertation explores the syntax and semantics of positive and comparative gradable adjectives. A detailed study of intransitive (*tall*) and transitive (*patient with Mary*) adjectives is provided with special emphasis on phrases that express the standard of comparison, such as tall for a jockey, tall compared to Bill, and taller than Bill. It is shown that standard expressions, surprisingly, behave differently both syntactically and semantically. There are four main conclusions. First, a syntactic analysis is provided in which all standard expressions are introduced by unique degree morphemes in the extended projection of the adjective. Each morpheme and the standard expression that it introduces is ordered such that for-PP's are introduced just above the adjective, followed by compared-to phrases and then comparatives. Thematic-PP's which denote the object of transitive adjectives are shown to be introduced in the extended projections as well, but interestingly, they are introduced between the for-PP and the compared-to phrase. Second, a neo-Davidsonian, event-style analysis is provided that completely separates the internal and external arguments of adjectives. Instead, gradable adjectives are treated as predicates of events (or states), simply. Arguments of the adjective are assigned theta-roles in the syntax and are integrated into the logical form through via conjunction. Third, all other parts of the meanings of positive and comparative adjectives are put into the denotation of the degree morphemes. This includes the comparison relation and the measure function. Thus, gradable adjectives are treated as the same semantic type as other adjectives and other predicates. And fourth, it is shown that positive adjectives are fundamentally different from comparative adjectives in a semantic sense. This is surprising because standard semantic theories of positives treat them as implicit comparatives. The primary difference is that positives are vague in a way that comparatives are not. It is shown that the difference is not a matter of context dependence as suggested in Fara (2000). Instead, it is suggested that the comparative morpheme is responsible for this difference. Therefore, grammatical processes can interact with vagueness in at least one way; they can reduce it.

This dissertation addresses a foundational debate regarding the role of structure and abstraction in linguistic representation, focusing on representations at the lexical level. Under one set of views, positing abstract morphologically-structured representations, words are decomposable into morpheme-level basic units; however, alternative views now challenge the need for abstract structured representation in lexical representation, claiming non-morphological whole-word storage and processing either across-the-board or depending on factors like transparency/productivity/surface form. Our cross-method/cross-linguistic results regarding morphological-level decomposition argue for initial, automatic decomposition, regardless of factors like semantic transparency, surface formal overlap, word frequency, and productivity, contrary to alternative views of the lexicon positing non-decomposition for some or all complex words. Using simultaneous lexical decision and time-sensitive brain activity measurements from magnetoencephalography (MEG), we demonstrate effects of initial, automatic access to morphemic constituents of compounds, regardless of whole-word frequency, lexicalization and length, both in the psychophysical measure (response time) and in the MEG component indexing initial lexical activation (M350), which we also utilize to test distinctions in lexical representation among ambiguous words in a further experiment. Two masked priming studies further demonstrate automatic decomposition of compounds into morphemic constituents, showing equivalent facilitation regardless of semantic transparency. A fragment-priming study with spoken Japanese compounds argues that compounds indeed activate morphemic candidates, even when the surface form of a spoken compound fragment segmentally-mismatches its potential underlying morpheme completion due to a morpho-phonological alternation (rendaku), whereas simplex words do not facilitate segment-mismatching continuations, supporting morphological structure-based prediction regardless of surface-form overlap. A masked priming study on productive and non-productive Japanese de-adjectival nominal derivations shows priming of constituents regardless of productivity, and provides evidence that affixes have independent morphological-level representations. The results together argue that the morpheme, not the word, is the basic unit of lexical processing, supporting a view of lexical representations in which there are abstract morphemes, and revealing immediate, automatic decomposition regardless of semantic transparency, morphological productivity, and surface formal overlap, counter to views in which some/all complex words are treated as unanalyzed wholes. Instead, we conclude that morphologically-complex words are decomposed into abstract morphemic units immediately and automatically by rule, not by exception.

The dissertation consists of theoretical and experimental studies of multiple interrogatives (i.e., sentences containing more than one wh-phrase, like Who bought what?). First, I examine the status of Superiority effects in contexts with and without subject-aux(iliary) inversion cross-linguistically. The relevant contrast from English is between Who bought what?, ??What did who buy?, and *I wonder what who bought., where (*) indicates a greater degree of unacceptability by native speakers than (??). I argue that the presence of subject-aux inversion in main clauses in English is responsible for the given asymmetry, and I attribute the degraded status of ??What did who buy? to the independent semantic properties of questions. Next, I explore the semantic properties of multiple interrogatives in detail. I develop an analysis that does not rely on covert wh-movement, relying instead on the syntactic position of the Question morpheme. I also explore the nature of complex wh-phrases (e.g., what boy, which book). I propose that choice functions are part of complex wh-phrases but not bare wh-phrases. I then explore the behavior of multiple interrogatives under Sluicing (i.e., clausal ellipsis). I observe that, in Slavic, it is possible to have multiple wh-phrases as well as focused referential expressions as remnants of sluicing. Based on this data, I argue that clausal ellipsis is licensed by focus in general. I also explore the apparent Superiority effects under sluicing in Russian and Polish and conclude that those are, in fact, parallelism effects, and not minimality effects. Finally, I present the results of several language acquisition studies on at what age and how English-, Russian-, and Malayalam- speaking children acquire the language-specific syntactic and semantic properties of multiple interrogatives, given the limited evidence in the input. I report the results of the corpus studies of parental speech with respect to the frequency of occurrence of multiple interrogatives, as well as the results of the studies, where multiple interrogatives were elicited from children and adults in specific contexts. I conclude that young children acquire syntax and semantics of multiple interrogatives quite successfully. I then discuss what evidence in the input they might be using.

The main goal of the work in this dissertation is to investigate pre-verbal structure building effects in languages with different configurations such as Spanish, Galician and Basque, by means of using different pre-verbal cues in order to show that syntactic structure can be both interpreted and anticipated before the verbal head. I examine the syntax of Clitic-Left Dislocations (CLLDs) and other kinds of left-dislocations in Spanish and then analyze their processing. I concentrate on the use of clitic pronouns in Spanish and Galician in CLLD constructions that require the presence of the clitic pronoun to interpret the left-dislocated phrase and where I examine if this left-dislocation is interpreted at the clitic pronoun. Experimental results from three self-paced reading experiments provide evidence that the clitic in these constructions is required and used to interpret the thematic features of the topicalized NP before the verb. Thus, I demonstrate that clitic pronouns are used as pre-verbal cues in parsing and that the active search mechanism is also triggered in long-distance dependencies involving clitic pronouns. I conclude that the active search mechanism is a more general architectural mechanism of the parser that is triggered in all kinds of long-distance dependencies, regardless of whether the search is triggered by gaps or pronouns. In Basque, verbal auxiliaries overtly encode agreement information that reflects the number of arguments of the verbal head. In negatives, auxiliaries are obligatorily fronted and split from the verbal head with which they otherwise form a cluster. Thus, verbal auxiliaries in Basque are a pre-verbal morphological cue that can assist the parser in predicting structure. Specifically, I examine how predictions for the upcoming structure of the sentence are determined by agreement information on the number of arguments specified in the auxiliary and by the mismatch of this auxiliary with the case features of the NP that follows it. I provide results from a self-paced reading experiment to argue that the parser uses the information encoded in the auxiliaries and demonstrate that the mismatch of the auxiliary with the following NP can prevent the reader from following a garden-path analysis of the sentence.